Perhaps you should try some spelling variations:
nha thuoc » nhan thuc, nha hoc
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
xay hoi » xa hoi, tay hoi, cay phoi
dau vai » dau va, dau hai, dau tai
vai cau » va cau, van cau, vai cac
y dang » ky dang, 2 dang, _ dang
va dau » va dao
nuoc » quoc, duoc, ngoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y dang xay hoi. hieu van ((nam thuc) or (((nha thuoc) or (nha nuoc)))) va dau vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y dang xay hoi. hieu van ((nam thuc) OR (((nha thuoc) OR (nha nuoc)))) va dau vai cau tren.
• Adding a wildcard symbol may retrieve word variants: te sach y dang xay hoi. hieu van ((nam thuc) or (((nha thuoc) or (nha nuoc)))) va dau vai cau tren*.